class Solution2 {
    public int maxProfit(int[] prices) {
          int len = prices.length ;
          int[][] dp = new int[len][2] ;
          dp[0][0] = -prices[0] ;
          for(int i=1 ; i < len ; i ++){
             dp[i][0] = Math.max(dp[i-1][1]-prices[i], dp[i-1][0]);
             dp[i][1] = Math.max(dp[i-1][0]+prices[i] , dp[i-1][1]);
          }
      return Math.max(dp[len-1][0], dp[len-1][1]);

    }
}

